1. Field of the Invention
The present invention relates to a technique for removing deposits from an internal combustion engine, and in particular to a technique for removing deposits by means of controlling a variable valve mechanism.
2. Description of the Related Art
Deposits that accumulate in proximity to intake valves in internal combustion engines affect operation of the engine. Accordingly, removal of accumulated deposits or reducing accumulation of deposits has been standard practice. For example, JP1992-001404A discloses a technique that involves disposing a passage for directing intake air onto the head of the intake valve to reduce accumulation of deposits.
However, this technique entails adding a special device to the internal combustion engine, making the device more complicated overall.